Wireless communication networks have been extensively deployed to provide various communication content such as voice, video, packet data, messaging or broadcast services. Wireless communication networks may be multiple access networks that share available network resources to support many users. The multiple access networks may include a Code Division Multiple Access (CDMA) network, Time Division Multiple Access (TDMA) network, Frequency Division Multiple Access (FDMA) network, Orthogonal Frequency-Division Multiple Access (OFDMA) network, and Single Carrier FDMA (SC-FDMA) network. A user equipment (UE) may be placed in the coverage of multiple wireless communication networks capable of supporting different communication services. A suitable one of the wireless communication networks may be selected to serve the UE according to one or more criteria.
Circuit Switched Fallback (CSFB) refers to a technology that enables a UE placed in a cell of the LTE Evolved Universal Terrestrial Access Network (E-UTRAN) to receive circuit switched (CS) services (e.g. voice service, video service, SMS service, location service, and Unstructured Supplementary Service Data (USSD)) by use of CS domain network resources (e.g. Mobile Switching Center (MSC) or MSC server).
Meanwhile, one or more wireless networking schemes may use adjacent frequencies of the same frequency band. When multiple wireless networking schemes coexist, it is necessary to develop a method for providing time information to a user equipment for CSFB.